Ice maker with ice bin level control

ABSTRACT

A clear ice maker unit has a clear ice maker mechanism with a cascading water evaporator configured to make clear ice during ice making cycles. A controller uses fuzzy logic to control the clear ice maker and determine whether to initiate a next ice making cycle based on input signals from a thermistor in the ice storage bin. The controller will prevent initiation of an ice making cycle when the ice bin is at or below a threshold temperature. The controller will also prohibit ice making when the ice bin is at or below a second, slightly higher temperature for more than a prescribed period of time. In this way, the clear ice maker can recognize an uneven distribution of ice and maintain an optimal amount of ice in the bin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional patentapplication Ser. No. 60/862,340 filed on Oct. 20, 2006, and entitled“Ice Maker with Ice Bin Level Control,” hereby incorporated by referenceas if fully set forth herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not applicable.

BACKGROUND OF THE INVENTION

The present invention relates to the manufacture of ice, andparticularly to automated clear ice maker units.

A conventional ice maker forms ice cubes by depositing water in a moldattached to an evaporator and allowing the water to freeze in asedentary state. Such an approach results in clouded ice cubes resultingfrom air and impurities present within the frozen water.

It is also known to form ice by flowing water over a freezing surface toallow the air and impurities to separate from the water before freezinglayer-by-layer to form the ice cube. This eliminates the cloudingassociated with sedentary freezing. These “clear ice” makers using sucha flowing process have typically been used in commercial applications.One example of a clear ice maker is shown in U.S. Pat. No. 5,586,439,issued Dec. 24, 1996 to Schlosser et al. In that patent, water flowsover a vertically disposed evaporator plate whose surface definespockets. The water flows over the pockets, and an ice cube is formed ineach pocket. The ice cubes are harvested by passing hot vaporousrefrigerant through the evaporator in place of the cold refrigerant.

It is conventional for harvested ice cubes to fall into an ice bin wherethe ice cubes are stored until they are used. The ice bin can properlystore a certain maximum amount of ice cubes, and ice making must bestopped when the ice bin is full to prevent overfilling the ice bin.Overfilling the ice bin can cause ice to spill out of the ice maker whenthe ice maker door is opened. Overfilling the ice bin can also lead toice building up in the ice making assembly which can result in watertraveling down the built-up ice into the ice bin thereby melting the icestored therein.

The ice level in the ice bin can be sensed to control the production ofice and to prevent overfilling the ice bin. If the ice bin isrefrigerated, a mechanical arm or a light sensor can sense the ice levelin the bin and shut off power to the ice making assembly when the icereaches a certain level. The mechanical arm is pushed up by the icethereby throwing a switch that shuts down the ice making assembly.Optical mechanisms can have a light source, light sensor, and/orreflector that shut down the ice making assembly when the path of travelof the light is disrupted by the ice. If the ice bin is notrefrigerated, a thermostat located in the ice bin can interrupt thepower supply to the ice making assembly when the thermostat drops belowa certain temperature.

In some clear ice makers, the ice can fall out of the ice makingassembly as slabs of cubes. Usually, the slab falls into the ice bin andbreaks into individual cubes when the slab hits the bin or ice stored inthe bin. Sometimes, however, the slab does not break apart upon impactwith the bin or the stored ice. Slabs tend to fail to break apart whenthe ice bin is more full, and the slab does not fall very far beforehitting the stored ice. The slabs can then stack up to a side of the icebin so that the ice is not stored uniformly in the ice bin (e.g., a sideof the bin is full of stacked slabs and another side is empty).Mechanical arm, optical, and thermostat ice level sensors will detectthe improperly stacked ice and prevent more ice from being produced eventhough storage space in the ice bin is actually available. Thus, theamount of ice produced and the amount of ice stored in the bin isnegatively impacted.

SUMMARY OF THE INVENTION

The present invention provides a clear ice maker with a controller thatcan determine improperly stacked ice.

Specifically, in one aspect the invention provides an ice maker unithaving an ice maker mechanism disposed in an ice maker chamber of aninsulated cabinet, the ice maker mechanism being capable of producingice during a plurality of ice making cycles and depositing the ice intoan ice bin within the cabinet. The ice maker unit includes a sensordisposed in the cabinet to sense the temperature at the ice bin and anelectronic control having clock circuitry and fuzzy logic programmingfor controlling the ice maker mechanism. The control is electricallycoupled to the sensor to receive an input signal from the sensorassociated with a bin temperature. The control uses the fuzzy logicprogramming to determine whether to initiate a next ice making cyclebased on the bin temperature sensed by the sensor. The control initiatesthe next ice making cycle only if first and second conditions are met.The first condition is that the bin temperature is above a firstthreshold temperature and the second condition is that the bintemperature is not below a second threshold temperature for a prescribedtime period.

The sensor can be disposed at a height corresponding to a maximum icelevel in the ice bin. The second condition can correspond to an unevenice distribution condition in which ice is disposed in the ice bin at orabove the maximum ice level at only a portion of the ice bin.

The first threshold temperature can be essentially 33 degrees Fahrenheitand wherein the second threshold temperature can be essentially 34degrees Fahrenheit.

The prescribed time period can be set according to a time needed tocomplete a prescribed number of ice making cycles. The prescribed numberof ice making cycles can be three.

The ice maker unit can include a user input connected to the controller,wherein the first threshold temperature can be set by the user input.

The ice maker unit can be a clear ice maker unit with a clear ice makermechanism disposed in the ice maker chamber and capable of cascadingwater over a vertically disposed evaporator during a plurality of icemaking cycles, each ice making cycle resulting in the production of aquantity of clear ice.

The ice bin can not be cooled by a refrigeration system.

In another aspect, the present invention provides a clear ice maker unitwith a cabinet defining an ice maker chamber and an ice storage bin. Theice maker includes a clear ice maker mechanism disposed in the ice makerchamber and capable of cascading water over a vertically disposedevaporator during a plurality of ice making cycles, each ice makingcycle resulting in the production of a quantity of clear ice. Acontroller is configured to control the clear ice maker, the controllerconfigured to determine whether to initiate a next ice making cycle. Asensor is connected to the controller and disposed in the ice storagebin for sensing a bin temperature. The controller is configured toprevent the initiation of the next ice making cycle when the bintemperature is not above a first temperature and is less than or equalto a second temperature for a prescribed time period, wherein the secondtemperature is greater than the first temperature.

The evaporator can have a plurality of pockets therein, and the clearice maker mechanism can be capable of cascading water over theevaporator during the plurality of ice making cycles and depositingclear ice formed on the evaporator into the ice storage bin.

The sensor can be disposed at a height corresponding to a maximum icelevel in the ice bin.

The second temperature can be associated with an uneven ice distributioncondition in which ice is disposed in the ice bin at or above themaximum ice level at only a portion of the ice bin.

The prescribed time period can be set according a time needed tocomplete a prescribed number of ice making cycles.

The first temperature can be essentially 33 degrees Fahrenheit, thesecond temperature can be essentially 34 degrees Fahrenheit, and theprescribed time period can be essentially one hour.

The clear ice maker can include a user input connected to the control sothat the first temperature can be set by the user input.

The sensor can be a thermistor.

The ice storage bin can not be cooled by a refrigeration system.

In another aspect, the present invention provides a method for makingclear ice in a clear ice maker unit having a clear ice maker mechanismdisposed in an ice maker chamber of an insulated cabinet, the clear icemaker mechanism being capable of cascading water over a verticallydisposed evaporator during a plurality of ice making cycles anddepositing clear ice formed on the evaporator into an ice bin within thecabinet. The method includes detecting an uneven ice distribution in theice bin in which ice is disposed in the ice bin at or above a maximumice level at only a portion of the ice bin and prohibiting a next icemaking cycle following detection of an uneven ice distributioncondition.

The method can also include sensing an ice bin temperature at a maximumice level in the ice bin before initiation of the next ice making cycle,prohibiting initiation of the next ice making cycle if the bintemperature is less than or equal to a first temperature, andprohibiting initiation of the next ice making cycle if the bintemperature is less than or equal to a second temperature for more thana prescribed period of time.

These and still other features of the invention will be apparent fromthe detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a clear ice maker unit having thefeatures of the present invention;

FIG. 2 is a perspective view thereof similar to FIG. 1 albeit with itscabinet door open so that the interior of the cabinet is visible;

FIG. 3 is a perspective view of a clear ice maker evaporator of the icemaker unit of FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 5;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a sectional view of a partially filled ice bin with an unevenice distribution;

FIG. 7 is a sectional view of a partially filled ice bin with an evenice distribution;

FIG. 8 is a sectional view of a filled ice bin with an even icedistribution;

FIG. 9 is diagram of the refrigeration system of the ice maker unit ofFIG. 1;

FIG. 10 is a schematic of the control system of the ice maker unit ofFIG. 1; and

FIG. 11 is a flow chart for determining whether to initiate a next icemaking cycle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-2, a clear ice maker 30 includes a cabinet 32 withan upper forward opening 34 and an interior 36. The opening 34 is closedby a door 38 that is hinged to the cabinet 32. The interior 36 includesan ice making area 40 in the upper portion of the cabinet 32 and a binarea 42 below the ice making area 40. The ice making area 40 includes aclear ice maker assembly 44. As discussed below, the clear ice makerassembly 44 is electrically connected to a controller 46 and connectedto a refrigeration system 48. The bin area 42 includes a rectangular icebin 50. The bin area 42 and ice in the ice bin 50 are not cooled by therefrigeration system 48. Both the cabinet 32 and the door 38 are formedof inner molded plastic members and outer formed metal members with thespace filled with an insulating layer of foam material, all of which iswell known in the art. Thus, ice in the ice bin 50 is insulated from theambient air.

Referring now to FIGS. 2-5, the clear ice maker assembly 44 ispositioned in the ice making area 40. The clear ice maker assembly 44includes a metal evaporator grid 70 mounted in a plastic shroud 72. Theevaporator grid 70 has a series of vertical and horizontal dividers 70 aand 70 b, respectively, which extend from a rear wall 74 and betweenlateral edges to divide the evaporator grid 70 into a series of pockets.As best shown in FIG. 3, the horizontal dividers 70 b slope towards thebottom front of the evaporator grid 70.

The shroud 72 is formed of a plastic material such as a polypropylene orABS and is molded about the evaporator grid 70. The shroud 72 has acontinuous bulbous edge which engulfs the edges of the evaporator grid70. The shroud 72 has laterally extending wing portions 76 projectingfrom each end of the evaporator grid 70. A bib portion 80 of the shroud72 is disposed beneath the bottom edge of the evaporator grid 70 andcontains integral projecting deflector fins 82. Each deflector fin 82 isaligned with the center of a column of pockets in the evaporator grid70.

The shroud 72 also includes an inclined roof 86 disposed above theevaporator grid 70. A water distributor 88 is attached to the shroudwings 76 above the roof 86. As shown in FIG. 5, the distributor 88 has afloor 90 with a central well 92 at one edge. Spaced upright barriers 94a and 94 b extend from the floor 90 beyond the well 92. A second seriesof spaced barriers 96 a, 96 b, et seq. extend between the barriers 94 aand 94 b and a rear edge 98 of the floor 90. Water deposited in the well92 will be directed by the barriers 94 and 96 to flow uniformly over therear edge 98 and on to the inclined roof 86. The water will thereafterflow over the roof 86 of the shroud 72, and into and over the surfacesof the pockets in evaporator grid 70. Uniform distribution of the wateris further ensured by a guide 100 that has a top opening 102 thatreceives an end of a water tube 103 and a cylindrical wall section 104that fits around a portion of the well 92. The guide 100 fixes the watertube 103 at the middle of the distributor 88. The water tube is alsosecured in place by a rivet connection to the top of the cabinet 32.

An ice maker evaporator 108 is attached to the rear wall 74 of theevaporator grid 70. The ice maker evaporator 108 is a part of therefrigeration system 48 shown schematically in FIG. 9.

Referring now to FIG. 9, the refrigeration system 48 includes acompressor 120, an accumulator 122, the ice maker evaporator 108, a hotgas bypass 124, a condenser 126, a condenser fan 128, and a dryer 130.The compressor 120, condenser 126 and condenser fan 128 are located atthe bottom of cabinet 32 beneath the insulated portion, as shown in FIG.2. The evaporator 108 has an outlet line 132 that passes through theaccumulator 122 to the compressor 120. The output of the compressor 120is connected to an inlet of the condenser 126 having an outlet line 134connected to the dryer 130. A capillary tube 136 leads from the dryer130 to an inlet of the evaporator 108. As is known, the compressor drawsrefrigerant from the evaporator 108 and accumulator 122 and dischargesthe refrigerant under increased pressure and temperature to thecondenser 126. The hot refrigerant gas entering the condenser 126 iscooled by air circulated by the condenser fan 128. As the temperature ofthe refrigerant drops under substantially constant pressure, therefrigerant in the condenser 126 liquefies. The capillary tube 136maintains the high pressure in the condenser 126 and at the compressoroutlet while providing substantially reduced pressure in the evaporator108. The substantially reduced pressure in the evaporator 108 results ina large temperature drop and subsequent absorption of heat by theevaporator 108.

The hot gas bypass valve 124 is disposed in a line 138 between theoutlet of the compressor 120 and the inlet of the evaporator 108. Whenthe hot gas bypass valve is opened, hot refrigerant will enter theevaporator 108, thereby heating the evaporator 108 and evaporator grid70.

Referring now to FIGS. 3-5, a water sump 140 has a trough portion 142extending beneath the evaporator grid 70. The trough 142 extends alongthe one side wall of the cabinet 32, along a rear wall, and to anopposite side wall of the cabinet 32. The bottom of the trough portionslopes downwardly to the level of a well 144 in which an inlet 146 of awater pump 148 is mounted. An outlet of the water pump 148 is connectedto the well 144 in the distributor 88. A removable stand pipe 152extends into the sump 140 and leads to an overflow pipe 154. The standpipe 154 opens to a drain 156 in the bottom of the bin area 42 in thecabinet 32. The drain can be connected to a drain in the home plumbing.Alternatively, the drain may lead to an overflow collector in the spacebeneath the insulated portion of the cabinet 32. Fresh water from anexternal source may be provided periodically to the sump 140 through awater fill valve.

In general operation, water from the sump 140 is pumped by the pump 148to the distributor 88 which delivers a cascade of water over thesurfaces of the evaporator grid 70. When the evaporator 108 is connectedto receive liquefied refrigerant from the condenser 126, the watercascading over the surfaces of the evaporator grid 70 will freeze inlayers and build up to form cubes of ice in the pockets. The pure waterfreezes first and impurities in the water will be left in suspension inthe flowing water. Once the ice cubes are formed, the hot gas bypassvalve 124 is opened and heated refrigerant is delivered to theevaporator 108, thereby warming the surface of the evaporator grid 70until the ice cubes dislodge from the evaporator plate grid 70. Thedislodged ice cubes will fall into the bin 50 and are directed away fromthe trough portion 142 of the sump 140 by the fins 82. Not all watercascading over the surface of the evaporator plate will freeze. Theexcess water is collected in the trough 142 and returned to the well 144where it is re-circulated to the distributor 88 by the pump 148. Duringice harvest (after each freezing cycle), a charge of fresh water isdelivered to the sump 140 by the water fill valve to dilute the waterand flush impurities through the overflow pipe 152 and out the drain.

Referring now to FIG. 10, the clear ice maker 30 includes an electricalsystem 170 for controlling the operation of the compressor 120, asolenoid 172 for the hot gas bypass valve 124, a solenoid 174 for thewater fill valve, condenser fan 128, and the water pump 148. Thecontroller 46 is a microprocessor that operates by programmed logic andin response to sensor and user inputs. The electrical system 170includes a bin thermistor 176 and a liquid line thermistor 178 disposedin the outlet line of the condenser 126. The bin thermistor 176 ismounted to the ice bin 50 at a bin thermistor height 180 as discussedhereinafter. The thermistors are commercially available conventionalparts. A user interface control unit 182 mounted near the top of theclear ice maker 30 receives user commands. The control unit 182 includesa display panel 184, a power input 186, a warmer input 188, a coolerinput 190 and a light input 192.

Upon initial start-up or restarting with the temperature of the binthermistor 172 above 35 degrees Fahrenheit, the controller 46 energizesthe hot gas bypass solenoid 172 and the water inlet valve solenoid 174for a period of time. This will fill the sump 140 with fresh water tothe level of the overflow pipe 152. Thereafter, the compressor 120, thecondenser fan 128 and the water circulation pump 148 are energized.After a short period of time, such as ten seconds, the water fill inletvalve solenoid 174 and the hot gas bypass solenoid 172 are de-energized.The ice maker 30 is now in a freeze cycle of an ice making cycle.

After a certain predetermined period of time into the freeze cycle, suchas four minutes, a reading of the liquid refrigerant temperature sensedby the thermistor 178 is taken. This temperature reading will determinethe remaining length of time for the freeze cycle and may also be usedto set or adjust the duration of the ice harvest cycle. The higher thetemperature of the liquid refrigerant, the longer the freeze cycle. Forexample, if the liquid refrigerant temperature is 80 degrees Fahrenheit,the total freeze time will be about 14 minutes. If the sensedtemperature is 100 degrees Fahrenheit, the total freeze time will beabout 22 minutes. At a temperature of 120 degrees Fahrenheit, the freezetime will be about 30 minutes.

The controller 46 is programmed so that once an ice making cycle hasbeen initiated, the ice making cycle will continue to completion throughice harvest regardless of the temperature reading of the bin thermistor176. This prevents the ice making cycle from terminating prematurelythereby ensuring that full-sized ice cubes are formed. When the freezetime has elapsed, controller 46 causes the clear ice maker 30 to enterice harvest mode in which the compressor 120 remains energized while thewater pump 148 and condenser fan 128 are de-energized and the solenoidsfor the hot gas bypass valve 124 and the water inlet valve 160 areenergized. The hot refrigerant gas flowing through the ice makerevaporator 120 will loosen the ice formed in the pockets of theevaporator grid 70 so that the ice can fall into the ice bin 50. Atypical harvest cycle lasts approximately 2-3 minute. The length of theice harvest cycle can be dependent upon the reading of the liquid linethermistor 178. The length of the harvest cycle would thus be adjustedinversely based upon the first sensed temperature of the liquid linethermistor. For example, if the sensed temperature of the liquid linethermistor 178 is 80 degrees Fahrenheit, a harvest cycle of 2 minuteswould be used. If the temperature is 100 degrees Fahrenheit or above,the harvest cycle will be reduced in time to 1.5 minutes. The harvestcycle can also be made constant for a range of temperatures or entirelyindependent of the temperature of liquid line thermistor 178.

At the conclusion of the harvest cycle, the controller 46 determineswhether to initiate another ice making cycle based on the temperature ofthe ice bin thermistor 176, which indicates the level of the ice in theice bin 50. The ice bin 50 is not cooled by the refrigeration system 50;therefore, the temperature of the ice bin thermistor 176 is determinedby the ice in the ice bin 50. As the ice fills the ice bin 50, the iceapproaches the bin thermistor 176, which causes the bin thermistor 176to be cooled. When ice is adjacent to the ice bin thermistor 176 and thebin 50 is uniformly filled with ice, the temperature of the ice binthermistor 176 will be at its lowest. Thus, the temperature of the icebin thermistor 176 can be used to control the height of the ice in theice bin 50 by stopping the production of ice when the temperature of theice bin thermistor 176 indicates that ice is adjacent to the binthermistor 176. The ice bin thermistor height 180 can be set to equalthe maximum desired ice level in the bin 50 in order to ensure that thebin 50 is not overfilled and to maximize ice production.

Referring to FIG. 8, when the ice fills the ice bin 50 uniformly, theice level is at or minimally above the bin thermistor height 180 and iceis adjacent the ice bin thermistor 176, the temperature T_(B) of the binthermistor 176 will be equal to or less than a temperature T1. Thetemperature T_(B) of the bin thermistor 176 may also be equal to or lessthan temperature T1 when the ice fills the ice bin 50 non-uniformly butthe ice is stacked against the wall of the bin 50 to which the binthermistor 176 is attached. The controller 46 can be programmed toprohibit the initiation of further ice making cycles when thetemperature T_(B) of the bin thermistor 176 is less than or equal totemperature T1. The temperature T1 can vary depending on theconfiguration of the ice maker 30 and/or environmental conditions. In anembodiment, T1 can be set to 33 degrees Fahrenheit.

Referring now to FIG. 6, it is possible that ice will not also stack upuniformly across the ice bin 50. This can be caused if the slabs of iceare not broken apart into ice cubes when the slabs fall into the bin 50.When the ice does not stack up uniformly across the ice bin 50, it ispossible that the ice will reach the maximum desired ice level on one ormore sides of the ice bin, but the ice will not be positioned adjacentthe ice bin thermistor 176. Thus, the temperature T_(B) of the ice binthermistor 176 will not reach a temperature below temperature T1, whichmeans that ice production would not be halted and more ice would beproduced. Additionally, the ice may stack up non-uniformly across theice bin 50 so that ice may be adjacent the bin thermistor 176, but thevolume of ice adjacent the bin thermistor 176 may not be large enough tocool the bin thermistor 176 sufficiently to reach a temperature belowT1. As shown in FIG. 6, the bin 50 has more room for ice, but wouldoverfill after more than a few further ice making cycles without thetemperature T_(B) of the ice bin thermistor 176 reaching temperature T1.The temperature T_(B) of the ice bin thermistor 176 may not reach atemperature below temperature T1, but the temperature of the ice binthermistor 176 will reach a temperature near temperature T1 as the bin50 fills up with ice. To prevent overfilling the bin 50 when the ice isnot stacked correctly in the bin 50, the controller 46 can use fuzzylogic to prohibit the initiation of further ice making cycles when thetemperature T_(B) of the bin thermistor 176 is less than or equal totemperature T2 for a period of time X. A temperature T_(B) of thermistor178 below temperature T2 indicates that the bin 50 is nearly full of iceand/or the ice is not stacked uniformly, which means that the bin 50 hasroom for more ice, but not too much more ice. The length of the periodof time X can be set to allow for the appropriate number of further icemaking cycles. The temperature T2 and the period of time X can varydepending on the configuration of the ice maker 30 and/or environmentalconditions. In one embodiment, for example, the temperature T2 can beset to 35 degrees Fahrenheit and the period of time X can be set to onehour to allow for three more ice making cycles, which maximizes iceproduction and minimizes the risk of overfilling the bin 50.

During operation of the ice maker 30, the controller 46 monitors thetemperature T_(B) of the ice bin thermistor 176, and logs into memorythe temperature T_(B) of the ice bin thermistor 176, and the time thetemperature reading was taken so that the controller 46 can analyze thehistorical temperature data to calculate the time that the temperatureT_(B) of the ice bin thermistor 176 is below temperature T2.Alternatively, the controller 46 can be configured to track the periodof time that the temperature T_(B) of the ice bin thermistor 176 isbelow temperature T2.

FIG. 11 shows a decision making process 200 of determining whether toinitiate an ice making cycle 202. Beginning with an ice making cyclecompletion 204, the controller 46 determines at decision block 206whether the temperature T_(B) of the bin thermistor 176 is less than orequal to temperature T1. If the temperature T_(B) of the bin thermistor176 is less than or equal to temperature T1, the controller 46 does notinitiate the ice making cycle 202 and the controller 46 stays indecision block 206. If the temperature T_(B) of the bin thermistor 176is greater than temperature T1, the controller 46 determines at adecision block 208 whether the temperature T_(B) of the bin thermistor176 is less than or equal to temperature T2 for more than the period oftime X. If the temperature T_(B) of the bin thermistor 176 is less thanor equal to temperature T2 for more than the period of time X, thecontroller does not initiate next ice making cycle 202 and returns todecision block 206. If the temperature T_(B) of the bin thermistor 176is greater than temperature T2 for more than the period of time X, thecontroller 46 initiates the next ice making cycle 202. At the end of theice making cycle 202, the controller 46 returns to ice making cyclecompletion 204 and restarts the decision making process 200. In anembodiment, the temperature T1 can be 33 degrees Fahrenheit, thetemperature T2 can be 34 degrees Fahrenheit, and the period of time Xcan be one hour.

In order to adapt the ice maker 30 to different environments, runningconditions and user preferences, the temperature T1 can be set by auser. For example, the ice maker 30 can be run until the ice bin 50 hasa user desired level of ice. The user can then access the currenttemperature T_(B) of the bin thermistor 176 and set temperature T1 to beequal to the current temperature T_(B) of the bin thermistor 176. Thecontroller 46 is configured so that the user can set temperature T1through the control unit 182. The user can access current temperatureT_(B) of the bin thermistor 176 through the control unit 182.Temperature T2 can be set to equal temperature T1 plus two degrees.Alternatively, the user can also set temperature T2.

It should be appreciated that merely a preferred embodiment of theinvention has been described above. However, many modifications andvariations to the preferred embodiment will be apparent to those skilledin the art, which will be within the spirit and scope of the invention.Therefore, the invention should not be limited to the describedembodiment. To ascertain the full scope of the invention, the followingclaims should be referenced.

1. An ice maker unit having an ice maker mechanism disposed in an icemaker chamber of an insulated cabinet, the ice maker mechanism beingcapable producing ice during a plurality of ice making cycles anddepositing the ice into an ice bin within the cabinet, the ice makerunit comprising: a sensor disposed in the cabinet to sense thetemperature at the ice bin; and an electronic control having clockcircuitry and fuzzy logic programming for controlling the ice makermechanism, the control being electrically coupled to the sensor toreceive an input signal from the sensor associated with a bintemperature, the control using the fuzzy logic programming to determinewhether to initiate a next ice making cycle based on the bin temperaturesensed by the sensor, wherein the control initiates the next ice makingcycle only if first and second conditions are met, wherein in the firstcondition the bin temperature is above a first threshold temperature andin the second condition the bin temperature is not below a secondthreshold temperature for a prescribed time period.
 2. The ice makerunit of claim 1, wherein the sensor is disposed at a heightcorresponding to a maximum ice level in the ice bin.
 3. The ice makerunit of claim 2, wherein the second condition corresponds to an unevenice distribution condition in which ice is disposed in the ice bin at orabove the maximum ice level at only a portion of the ice bin.
 4. The icemaker unit of claim 1, wherein the first threshold temperature isessentially 33 degrees Fahrenheit and wherein the second thresholdtemperature is essentially 34 degrees Fahrenheit.
 5. The ice maker unitof claim 1, wherein the prescribed time period is set according to atime needed to complete a prescribed number of ice making cycles.
 6. Theice maker unit of claim 5, wherein the prescribed number of ice makingcycles is three.
 7. The ice maker unit of claim 1, further comprising auser input connected to the control, wherein the first thresholdtemperature can be set by the user input.
 8. The ice maker unit of claim1, wherein the ice maker unit includes a clear ice maker mechanismdisposed in the ice maker chamber and capable of cascading water over avertically disposed evaporator during a plurality of ice making cycles,each ice making cycle resulting in the production of a quantity of clearice.
 9. The ice maker unit of claim 1, wherein the ice bin is notrefrigerated.
 10. A clear ice maker unit, comprising: a cabinet definingan ice maker chamber and an ice storage bin; a clear ice maker mechanismdisposed in the ice maker chamber and capable of cascading water over avertically disposed evaporator during a plurality of ice making cycles,each ice making cycle resulting in the production of a quantity of clearice; a controller configured to control the clear ice maker, thecontroller configured to determine whether to initiate a next ice makingcycle; and a sensor connected to the controller and disposed in the icestorage bin for sensing a bin temperature; wherein the controller isconfigured to prevent the initiation of the next ice making cycle whenthe bin temperature is not above a first temperature and is less than orequal to a second temperature for a prescribed time period, wherein thesecond temperature is greater than the first temperature.
 11. The clearice maker unit of claim 10, wherein the evaporator has a plurality ofpockets therein, and wherein the clear ice maker mechanism is capable ofcascading water over the evaporator during the plurality of ice makingcycles and depositing clear ice formed on the evaporator into the icestorage bin.
 12. The clear ice maker unit of claim 11, wherein thesensor is disposed at a height corresponding to a maximum ice level inthe ice bin.
 13. The clear ice maker unit of claim 12, wherein thesecond temperature is associated with an uneven ice distributioncondition in which ice is disposed in the ice bin at or above themaximum ice level at only a portion of the ice bin.
 14. The clear icemaker unit of claim 13, wherein the prescribed time period is setaccording to a time needed to complete a prescribed number of ice makingcycles.
 15. The clear ice maker unit of claim 14, wherein the firsttemperature is essentially 33 degrees Fahrenheit, the second temperatureis essentially 34 degrees Fahrenheit and the prescribed time period isessentially one hour.
 16. The clear ice maker unit of claim 10, furthercomprising a user input connected to the controller, wherein the firsttemperature can be set by the user input.
 17. The clear ice maker unitof claim 10, wherein the sensor is a thermistor.
 18. The clear ice makerunit of claim 10, wherein the ice storage bin is not refrigerated.
 19. Amethod for making clear ice in a clear ice maker unit having a clear icemaker mechanism disposed in an ice maker chamber of an insulatedcabinet, the clear ice maker mechanism being capable of cascading waterover a vertically disposed evaporator during a plurality of ice makingcycles and depositing clear ice formed on the evaporator into an ice binwithin the cabinet, the method comprising: detecting an uneven icedistribution in the ice bin in which ice is disposed in the ice bin ator above a maximum ice level at only a portion of the ice bin; andprohibiting a next ice making cycle following detection of an uneven icedistribution condition.
 20. The method of claim 19, further including:sensing an ice bin temperature at a maximum ice level in the ice binbefore initiation of the next ice making cycle; prohibiting initiationof the next ice making cycle if the bin temperature is less than orequal to a first temperature; and prohibiting initiation of the next icemaking cycle if the bin temperature is less than or equal to a secondtemperature for more than a prescribed period of time.